Colored oxide film on metals consisting of the class of aluminum and alloys thereof and process of producing same



ll a'lenteil Apr. 8, i941 11;. TE D STAWI ii" wil i -7 in, Mad, may

tilt in ii 2,2WAW3 COLORED OXIDE mill l UN METrtllili limit- PRiJDUGiNiG: E-i

Switaerland No Drawing. Apnlication .liilnu" rial lilo llfitfii lll. lin iivvltiicrlani l liannai'gv lit,

(iDl. l lli di with 7 Claims.

This invention relates to the dyeing of an oxide film on metals consisting of the class of alumi horn and an alloy thereof with vva'ter soluble acyl derivatives of the dyestuffs as are described in Patents Nos. 2,120,741, 2,095,600 and 2,120,7i3 as Well as in patent applications Serial No. 922%, tiled July 23, 1936, issued Aug. 22, 1.939 as U. S. Patent No. 2,170,262, and Serial No. 173,528, filed l l'ovenriber 8, 1937, and further in British l-atent No. 480,353.

These acyl derivatives of dyestuffs are quite aenerally obtained by causing to react, in the presence of a tertiary base, such as pyridine, sparingly Water-soluble dyestuffs containing at least one substituent incapable of forming salts stable to Water selected from the group consistinc oi Oliand l llihgronps, with acylatine' aaents containing at least one acid halide group and at least one group which imparts increased vvateneolubillty to the acylation product formed. roducts thus obtained are characterized'hy the following common propertles:--The wateraolubility which is due to the acyl-eroup; the capability of being-easily split While regenerating the sparingly soluble parent dyestufi! by dilute aqueous solutions of saponiiylng agents, such as dilute aqueous solutions of allralies. Dyestuffs suitable for producing; the acyl derivatives are,

tor example, azo-clyestuffs which are produced by coupling dlazotized amines with hydroiry compounds capable of coupling, provided that the dlaao-c0mpound and the coupling compo-- nent do not contain groups lending solubility or aroups lending so little solubility that the dyestufi produced is practically insoluble in Water. The coupling components may contain a hydroiryl aroup, which determines the coupling, in an isocy'clicor hcterocyclic-ring, or in an open chain. lElesldes the acn -dyestuffs, dyestuffs of other classes are suitable, for instance dyestuffs of the antln'aquinone series Which contain a hydronyl ail-cup; also hydroxyl derivatives of suitable dyestuffs of. the acine, oaazine, thlazine, arylniethane and pyi'one series.

" uct.

, halide.

insoluble dyestuilfs, in which the sal'tdorlning group which yields no salt stable to Water is an bills or NH, may themselves belong to the aforesaid dyestuff series. They may also, for instance, be condensation products of cyanuric chloride with amines, which still contain chroniophore groups, for example azmgroups.

The Water-soluble decomposable derivatives of Water-insoluble dyestuffs oi the hind described above, which are required in the invention, are obtained by the action of a. compound having least one acid halide group and at least one sub stituent which of itself or after suitable change determines an enhanced solubility of the prod- Eiuch compounds are, ior instance, aliphatic, cycloaliphatic, aliphatlmaromatic or aromatic carhoirylic acid halides or sulionic acid icr example acid chlorides or acid lironudes. Specific instances are sulfoac-etyl chic-- ride, sulfofuranecarboirylic acid chloride, suliobenzoyl chloride, benaoic acid suifochloride, benaenehcnacarhoaylic acid dichloride and trichloride, naphthalenetrisulfochloride, products of reaction of sulfur trioinde on benaoyl chloride and oi chloro-sulionic acid on benzoic acid. 'lo these compounds belong; also purely inorganic acid halides oi. polybasic acids, for instance chlorosulfonie acid, which must be regarded sulfuric acid nionochloride; The said acid halide groups are in condition to react with the aio said salt-forrnine groups of the dyestuils to to n compounds capable of scission. The further sub-- stituent sent the acid halide molecule, which dete nines the enhanced soltibilit oi? the product of neaction, either of itself or after suit able chance, may he any group capable of dis soclation, for instance carbonyl group or a sui fonlc acid aroup, ivhic" has the effect that the compound obtained it n anion. in the some effective if lily :o en atom is can i "s. sociation, :loi instance phenolic 01 crew polyluvdrlc phenols or Elli-groups which are sulpstituenta of an inorcanic acid, that is at least dibasic, for example the OH-group of chlorosulionic acid HO---SO2C1.

Substituents which after suitable change, enhance the solubility of the product obtained, are, for example, halogen atoms which can combine with a tertiary amine, for instance pyridine, trimethylamine or triethylarnine, to form quaternary ammonium compounds and produce the effeet that the compound obtained can pass into the solution as a cation. In the same sense other substituents are effective, for instance tertiary amino-groups, which can combine with halogen hydrocarbons to form quaternary compounds, also thio-ethers or the like.

Reaction between the aforesaid insoluble dyestuffs and the aforesaid acid halides may be conducted with advantage by heating together the two components in a tertiary base acting as a solvent, for instance pyridine or dimethylaniline. Further data on the manufacture of the acyl derivatives used here are found in the patents and patent applications hereinbefore mentioned.

The oxide film on metals consisting of the class of aluminum and an alloy thereof which is to be dyed according to the present process may be obtained by various processes, for instance preferably by electrolytic oxidation, such as in a bath containing sulfuric acid, oxalic acid, ammonium bicarbonate or chromic acid, or also by a purely chemical oxidation, such as can be produced in an acid or an alkaline bath containing, for instance, a salt of chromic acid or of hydrofluoric acid or of hydrofluosilicic acid and, if desired, another heavy metal salt, for instance a represents an acyl radical containing at least one group causing the solubility of the product, is preferabl efiected in two stages, 1. e., by bringing first of all the acyl derivatives of the dystufis into contact with the material to be dyed (dye 'ing) and then regeneratin (saponifying) the dyestuff.

Among the products of the above explained general formula R1OR2 those are again particularly valuable wherein R1 represents a radical derived from a sparingly soluble azo-dyestufi obtained itself from a diazo-compound free from carboxyland sulfo-groups combined with an arylide of the 2:3-hydroxynaphthoic acid which is also free from sulfo-groups and carboxylgroups, and wherein R2 represents a benzoyl radical containing at least one and at the most two sulfa-groups.

The oxide film on metals consisting of the class of aluminum and its alloys may be dyed in various manner; for example, the oxide film may be treated with a solution of the acyl derivative of the dyestufi" in water, alcohol, acetone, pyridine and the like, or the solution may be sprayed onto the oxide film or painted on it, or the dyestuff may be printed in the form of a paste on the oxide film. According to the nature of the acyl derivatives of the dyestuffs the dye-bath may be neutral or weakly alkaline, and may contain additions such as Glaubers salt, or it may be acid, containing mineral acid or oraasaaes garlic acid. The temperature of the dye-bath may vary within wide limits. For obtaining the best results, however, it is in many cases of advantage to suit the temperature of the dye-bath to the degree of hydration of the oxide film.

Dyeing may also be effected in such a manner that it is carried out simultaneously with the production of the oxide film on metals consisting of the class of aluminum and an alloy thereof. This modification has the advantage that there is only one stage in the process.

If the oxide films have been dyed with such acyl derivatives of the dyestuffs which are saponifiable by alkalies, they are treated with dilute solutions of weak alkalies,. for instance with dilute ammonia or sodium carbonate solution. If, however. the oxide films have been dyed with acyl derivatives of dyestuffs capable of being decomposed by acids, they are treated with dilute mineral acids or dilute organic acids. In both cases .the oxide film is dyed intensive tints which are characterized by their surprising properties, particularly their beauty and their fastness to water and rubbing.

The products obtained according to the present invention represent therefore compositions of matter consisting of two components, viz. an oxide film on aluminum and a sparingly soluble dyestuff containing at least one substituent incapable of forming salts stable to water selected from the group consisting of OH- and NH-groups. Amongsuch compositions of matter those are particularly valuable in which the oxide film of aluminum is electrolytically produced, and the sparingly soluble dyestuff is a sparingly soluble azo-dyestuff, such as for example a dyestuff obtained from a diam-component free from sulfogroups and carboxyl-groups and an arylide of the 2 S-hydroxynaphthoic acid.

The success of this process is entirely surprising, for there were no data available that dyeings produced in such a manner would be fast,

particularly fast to water and rubbing. Further,

such oxide films cannot be colored with ester- J like derivatives of leuco compounds of vat dyestuffs such as are marketed under the registered name Indigosol.

With regard to the production, properties, and enumeration of the acyl derivatives of the dyestuffs which are applied here, reference is again made to the publications mentioned at the beginning of this specification. The application of the process is illustrated by the following examples, the parts being by weight:

Example 1 1 part of the reaction product obtained by causing metasulfobenzoyl chloride to act on the azo-dyestufi from diazotized 2-methyl-4-nitrani line and 2:3-hydroxynaphthoic acid-ortho-toluidide, is dissolved in parts of water. A sheet of aluminum, the surface of which has previously been oxidized by electrolysis, is immersed for about hour at 50 C. in this dyestuif solution. The aluminum sheet is then rinsed with cold water and introduced for 20 minutes into a solution consisting of 900 parts of saturated common salt solution, 100 parts of water and 100 parts of an ammonia solution of 25 per cent strength. After thorough rinsing with water the aluminum sheet which is colored a nice bluish-red tint is dried. The coloring is intensive and very fast.

The followin table gives information on the colorings which may be obtained by using furcomco thor Writer-soluble ocyl derivatives of wotcrdocoltihlc ooo-clyestufls:

"llfhc iollo-Wiric tdlole rivet information on coloringo which moo loo ohtoiocci hr ooimr CUES oi o Azo-dyostufl v Acyiating agent omdmw aluminum o l r Aminochloranisol(0CHaNH C11:2:4)l- 2:3 hydrorynaphthoicacid- Belizoio acid-ii-aulfochlorido Red.

ortho-onisidide. 2 Nitroltgluidinc (CHtNHnNOzdflA) -v-'-v2:3-hydroxyjnaphthoic acidom 1 e. t ii 4-( l-methy1)-phenoxyacetyl-amino-2:5-diethoxy-i-amino benzene ---u fizEi-hydroxy-naphthoic ocid-nniiide. ll flzfi-dichlorauiliue 2:3-hydroxynaphthoio acid-ortho-anisldido 5 i-chlorbcnzene-ezo-y-amino-iiflmethoxynaphthalene -'--o 2:3-hydroryno hthoic ocid-onilide. it out iominodiphenylether ---o 2: 3-hydroxynapl1tholc acld-anilide 7i ilzii-dichloraniline 2z3-hydroxynaphthoic acld-anilldc it Aminochloranisol (OCH3NHaCl:1,2,4) 2:3-hyl iroxy-naphthoic acidortho-onisidido. ll Aniline-d a.-naphthol... 11o llnilino -d2:4-dihydroxy-quinoline. .dol.-.. so Yellow 11 Dionisidino--1fl-napl1thol l Suliosolicyhc acid-dichloride. Blue. 112 :i-omino-ozobcnzone--+-.B-naphthol. Benzoic ocid-3-sulfochloride BOidBilLlt iii azfi'diamlnobenzanilidefi p-cresoli. .,f.. do Yellow. lo 0rtl1o-ominoazotoluene,--- fi-nephthol 1-bonzoylamino-3benzcnc-carboxyiic ac1d-3; 5- Bordecnr.

t i disullochloride. it Ortho-aminoazotoluene roam-amino. 113:6-naphthalene-trisulionic acid-chloride Brown. 1d i-omlnonophthalcncM \mi ide oi2:3-l.iydroxynaphthoic acid. 1:3:G-rmphthalcne-trisulfochloride. Box-doctor. 17 Mcto-chloranilinefi onilid cioi2:i -l1:, droxynaphtlioicacid...- Nophthoic ecid-dlsuifochiorido. l Orange. lit 41(i methyi)-phenoxyacetylamiiro-Zzd-dimethoxy-l-aminohemzenc Furone'om sulfocarboxylic acid chloride Blue.

onilidc of 2:3-hydroxy-naphthoic ilcld. lil Dionisidine---v-fl-naphthol no il-GhlOfgrmtbyl-bcnzoyl chloride in presence of Violet.

' I pyr me. iii) 2-n1ethyl i:4diamino-5-methoxyazobenzene d-nophthol do Do. an l-nophthylomine--n9-naphthol do.. -ii e Bordeaux. 22 l-nophthylomine --o fi-naphthoh. .1 Nlcotimc ocld chloride in presence of pyridine... Do.

i l I v t l 1 Emmple'z oiroiior monitor further ocyl derivatives oi this i port of the reaction product obtoioed by llrirrd:

Color of the Dycstuii Acyloting agent oxidized aluminum 1 Condensation product from 1 mol cyonuric chloride, 2 mols Pomw-chloromethyl-benzoyl ciilo- Yellow,

. z-aminoanthmquinone and 1 mol ominopyrcno. ride (in the presence of pyridine). l 3 Condensation product from 1 mol cynnm'io chloride, 1 mol o; .5 Do.

aniline and 2 mols 4-amino-3:2-dimethy1ozo-lacnzene. l 1 8 4-bcnzoylcminoazo-benzenc "do u Do.

Wi here is obtained a nice, fost yll'ow coloring.

, The following tab 1e giv'es informatioh on the 50 colorirlcs which may be obtained by "usinc/irt olmilor roonrrcr further ocyl derivatives; oi this I r Example ti 5 "the reaction product which. is olotoizoed hr cousing 3:5disulfbbcnzoyl chloride to cot on tho disozmdyestofl produced by coupling E ill'id'iil'itidlili? didzoberizcne cud itz5-dimethyl-lmooinolzreriocric,

diofzzotizing this ornihoozo dyestuiit cod co'dmlirrei with 3 mcthyl l-ch1orophehol, is dissolved hr tho hundred told quantity oi? water. dccordirrrr to the process described in Exomple i, nice, brown colorings ore obtained on olurriioum.

islnromolc ii ltllliilla lihe-rcoctiorr product which is fGlllTlEd by coun o 1 m i 0 or 0 ie F U Acylating agent oxidized 1 aluminum i ll-bcnroylomino-Ii:2'- imethylazo enzeno Bcncoic fiGld-{iZB-(llsulfo omm n" w, 2 J Condensation product from 2 mole. 4-amino-azobenzene and 1 d DQ rnol mo-dichloroquinazoline. t a Condensation product from 3 mols 4-amino-3:2'-dimethyiocobcnmoo zone and 1 mol cyanuric chloride. i Z-ocet lominoanthmquinonefi. .dhdo D 5 00nd nsotlon product iroml moi cyzmun'c ocid chloride, 2 mol Benzoic acid motosuiio chloride Rcd.

iomiuoi-methoxyanthraquinone and 1 molommonlo. o Condensation product from 1 mol i-n.rnin mzober\zone 1 mol Eoll'o-clzloroocetio acid chloride M Yellow.

onilin and 1 mol2-eminoanthroquinooo.

Example hroc tly'the same result as in Example 2 is ohtoined if instead of the reaction product doocrihed in that example there is used the reoc .tion product which is obtained by causing int; disulffohenzoyl chloride to dot on tzii-dio1ryr 4t o di pom mothorrrheoooylominoorlthro oi. none, is dissolved in hundred fold quantity wotcrz, According to the proceed to Example 1, on intensive, first lEiordeoui: coloriimr is ohtoirred co olumiroum.

the following table gives iritormdtiori. on oolorilogo which may he obtained ht" moth to soluble dyestufis of the above type containing hydroxyl-groups:

duced oxide film on a metal selected from the class consisting of aluminum and alloys thereof,

Color of the D yestufi Acylating agent oxidized aluminum 1 1:5-dibenzoyldiamlno-4:S-dihydroxyantbra-quinone Benzoic acid-3:5-disuliochloride Blue-violet. 2 i-l1ydrory--para-tolylamino-anthraquinone -.d0. Do. 8 l:b-diamino-4:S-dihydroxyanthraqninone Benzoic acrd-(i-suliochloride Do. 4 Benz2-benz-2-dihydroxydibenzanthrone do Green. 5 l:5-dibenzoyldlamino-4:S-dihydroxyanthraquinone Cllloromethylbenzoylchlorido Blue-violet 6 Benzene-2-benzene-2-dihydroxydlbenzanthrone ..d Greene Example 6 To 1000 parts of an oxalic acid bath of 3percent strength used for producing an anodic fllrn on aluminum (Zeitschrift f. elektr. Chemie, vol. 3'7, pages 721-724) there are added parts of the reaction product which is obtained by causing meta-sulfo-benzoyl chloride to act on the tertiary condensation product from 1 mol of cyanuric chloride, 2 mols of Z-aminoanthraquinone and 1 mol of aniline in aqueous solution. In the subsequent anodic treatment the ester-like product is precipitated onto the oxide layer. The latter is colored an intensive, fast yellow tint when treated in known manner with dilute ammonia solution.

Example 7 Into a solution of 1 per cent strength of the sulfuric acid ester of the azo-dyestufi from diazotized 2 methyl-S-methyl 1 aminobenzene and para-cresol there is immersed at 40-50 C. a strip of anodically oxidized aluminum and the temperature of the solution is maintained for hour. The aluminum is thus colored clearly yellow. After rinsing with water for a short time the aluminum strip is developed by immersing it for some time at room temperature into a suliuric acid or acetic acid solution of /2 per cent strength, whereupon it is rinsed and dried. The tint is thereby displaced to a fast brown yellow.

The following table gives information on the colorings which may be obtained by using in similar manner further acyl derivatives of this kind:

which comprises treating the oxide film on metals consisting of the class of aluminum and an alloy thereof with a solution of a water-soluble acyl derivative of a sparingly soluble dystufl obtained by the reaction, in presence of pyridine, of a dyestufi containing at least one 011- group forming salts with alkalies which are hydrolyzed by water, with acylating agents containing at least one acid halide group and at least one group which imparts to the formed product increased water-solubility, and then with a solution of an alkaline saponifying agent.

3. A process of coloring an electrolytically produced oxide film on a metal selected from the class consisting of aluminum and alloys thereof, which comprises treating the oxide film on metals consisting of the class of aluminum and an alloy thereof with a solution of a water-soluble acyl derivative of a sparingly soluble azo-dyestuff obtained by the reaction, in presence of pyridine, of an azo-dyestuif containing at least one OH.- group forming salts with alkalies which are hydrolyzed by water, with acylating agents containing at least one acid halide group and at least one group which imparts to the formed product increased water-solubility, and then with a solution of an alkaline saponifying agent.

4. A process of coloring an electrolytically produced oxide film on a metal selected from the class consisting of aluminum and alloys thereof, which comprises treating the oxide film on metals consisting of the class of aluminum and an alloy thereof with a solution of a water-soluble Color of the Acylatlng agent in the Parent dyestufl oxidized presence of pyridine aluminum 1 'Irisazo-dyestutf from 1 mol tetrazotizcd 4:4-dlamino-Z-methyl-5-meth0xy- Chlorosulfonic acid N Brown.

azobenzene and 2 mole para-crcsol. 2 Monoazo-dyestuti from diazotized dehydrothiotoluidine and pare-cresol do Yellow. 3 Monoazo-dyestuti from diazotized 2-1nethoxy-5-methyl-l-arninobenzene and do Do,

l-liydroxy-2:4-dimethylbcnzcne. i Disazo-dyestufi from the diazotized monoazo-dycstufi from 4-chloro-diazo- .d0 Brown.

benzene and l-amino-2-mcthoxynaphthalcnc and Lhydroxy-ii-mcthyl-- chlorobenzene.

What we claim is:

l. A process of coloring an electrolytically produced oxide film on a metal selected from the class consisting of aluminum and alloys thereof, which comprises treating the oxide film on metals consisting of the class of aluminum and an alloy thereof with a solution of a water-soluble acyl derivative of a sparingly soluble dyestufi" obtained by the reaction, in presence of pyridine, of a dyestuii containing at least one salt forming group forming salts with alkalies which are hydrolyzed by water selected from the group consisting of OH and --NH groups, with acylsting agents containing at least one acid halide group and at least one group which imparts to the formed product increased water-solubility, and thenv with a solution of a saponifying agent.

2. A process of coloring an electrolytically proacyl derivative of a sparingly soluble azo-dyestuff obtained by the reaction, in presence of pyridine, of an azo-dyestuff containing at least one OH group forming salts with alkalies which are hydrolyzed by water, with halides of aromatic acids of the benzene series which contain one carboxyl group and at least one but not more than two sulfonic groups, and then with a solution of an alkaline saponifying agent.

5. A process of coloring an electrolytically produced oxide film on a metal selected from the class consisting of aluminum and alloys thereof, which comprises treating the oxide film on metals consisting of the class of aluminum and an alloy thereof with a solution of a water-soluble acyl derivative of a sparingly soluble az o-dyestuff obtained by the reaction, in presence of pyridine, of a sparingly soluble azo-dyestufi which is itself enemas obtained by uniting a diam-compound free from sulio and carboxyl groups with an arylide of 2:3- hydroxynaphthoic acid, with halides of aromatic acids of the benzene series which contain one carliozayl group and at least one but not more than two sulfonic groups, and then with a solution of an alkaline saponifying agent.

6. A process of coloring an electrolytically produced oxide film on a metal selected from the class consisting of aluminum and alloys thereof, which comprises treating the oxide film on metals consisting of the class of aluminum and an alloy thereof with a solution of a water-soluble acyl derivative of a sparingly soluble azo-dyestuff obtained by the reaction, in presence of pyridine, of a sparingly soluble azo-dyestufi which is itself obtained by uniting a diam-compound free from sulfo and carboxyl groups with an arylide of 2:3- hydroxynaphthoic acid, with halides of aromatic acids of the benzene series which contain one carhoxyl group and at least one sulfonic group, and then with a solution of an alkaline saponifying agent.

'7. An oxide film on a-metal selected from the class consisting of aluminum and alloys thereof and colored by a sparingly soluble azo-dyestufl obtained by the saponification of a water-soluble acyl derivative of an insoluble azo-dyestuff which is itself produced by the combination of a diazo compound and an arylide of 2:3-hydroxynaphthoic acid, said film being characterized by the excellent fastness of its color.

CHARLES GRAENACHER. MAX MATTER. 

